The new skills (like conjuring planks and triangles/floating platforms) can be aquired from chests hidden in the levels, you can then enhance those skills in the inventory menu which is opened by pressing "i" and using skill points aquired by collecting experience from vials and monsters.

Its possible that in the video the player had completed the entire game before hand and thus can have all the skills even in levels where you wont be able to have them on first playtrough.